Vertically mounted spike driver



y 5, 1959 c. E. GODFREY 2,884,867

VERTICALLY MOUNTED spm: DRIVER Filed Sept. 24, 1956 2 Sheets-Sheet l 5 i INVENTOR.

Ilka/Q55 E. EUDFR'EY May 5, 1959 2 Sheets-Sheet 2 Filed Sept. 24, 1956 H l l u INVENTOR. EHFIE'LES E. EUDFR'EY' BY M FIR- '5.

substantially during simultaneously, this efiect Ser. No. 602,688, filed August 2,884,867 vVERTICALLY MOUNTED SPIKE DRIVER iCharles E. Godfrey, Lombard, 111., assignor to American Brake Shoe Company, New York, N.Y., a corporation 7 of Delaware Application September 24, 1956, Serial No. 611,470 Claims. (Cl. 104-17) This invention relates to impacting apparatus and is particularly concerned with an apparatus including two impacting devices capable of effecting two impacting operations simultaneously.

The present invention is of particular value in railway construction and maintenance where it is customary to provide retaining and anchoring devices such as spikes or studs on opposite sides of each rail of therailway to secure the rail to a tie; these anchoring devices are passed through tie plates interposed between the rail and the tie and are effective to oppose relative movement between the tie plate, tie, and rail. It has been customary .to utilize a tie plate on each tie between the tie and the rail because the tie plate affords a relatively substantial 'area of contact in comparison with the much more limited area of the base of the rail which would otherwise be in contact with the tie. Each tie plate includes sections which extend respectively on opposite sides of the rail. Usually, four openings are provided in each such section in spaced relation with respect to each other, the inner- -most openings being so located that when retaining devices such as spikes are passed through these openings .and driven into the tie, the heads of the retaining devices engage the base of the rail and secure the rail and tie plate to the tie. To counteract side thrust impressed upon ever, they comprise studs of the type described and claimed in U. S. Patent No. 2,401,967, issued June 11,

.1946 or of the type disclosed in my co-pending application Ser. No. 131,781, filed December 8, 1949.

Heretofore, spikes, studs and other similar anchoring and retaining devices have been driven into railway ties by manually manipulated pneumatically operated hammers which, because their operation entails exceptional physical exertion, have usually been operated by crews of men in alteration. Following customary practice, in which one spike or stud is driven at a time, the individual spikes on one side of the tie plate may become loosened driving of spikes on the opposite When two hammers are utilized also frequently occurs because of the difliculty of synchronizing operation of two hammers by individual crew members. This difficulty in obtaining uniform plate has been substantially eliminated by a dual hammer apparatus which drives spikes on opposite sides of the tie plate concurrently and synchronously; impacting apparatus of this type is described and claimed in co-pending applications of Charles E. Godfrey and Wesley T. Johnson Jr., Ser. No. 509,297, filed May 18, 1955 and 2, 1956, which effectively side of the tie plate.

eliminate this problem.

In each of the aforementioned Godfrey and Johnson ing devices or hammers have been effected by means of anchorage on the two sides of the tie United States Patent 0 .inventions, relative alignment and guidingof the impactrice devices which afford means for adjustment, control and alignment of the hammers with respect to a three-dimensional series of rectangular coordinates. Thus, in each of these systems, the individual impacting devices'which operate on opposite sides of the rail are independently adjustably mounted for movement both longitudinally and transversely with respect to the rail and are guided for accurate vertical movement. In each of the aforementioned applications, moreover, the alignment and guiding arrangements project upwardly from a frame which constitutes the base of the impacting apparatus.

A primary object of the present invention is the provision of a new and improved suspension and alignment system in an impacting apparatus of the type described in the aforementioned Godfrey and Johnson applications.

An additional object of the invention is the provision of an impacting apparatus incorporating two individual impacting devices in which the alignment and guiding elements of the apparatus are extremely simple and consequently economical to manufacture.

Another object of the invention is the provision of a new and improved dual impacting apparatus in which the impacting devices may be accurately aligned with the spike-receiving apertures of a tie plate with a minimum of effort and skill on the part of the operator and in a minium time.

A further object of the invention is to afford a new and improved dual impacting apparatus which is convenient in operation and which afi'ords maximum ease of alignment by the operator thereof.

Accordingly, the invention is directed to an apparatus for driving spikes or like fastening devices into a railway tie and comprises a frame and rail-engaging wheels, mounted on the frame, for transporting and guiding the apparatus along a railway rail. A pair of horizontal support members are mounted on the frame for independent horizontal movement with respect to the rail; preferably the support members comprise cantilever arms mounted for pivotal movement about a common vertical axis and are located well above the railway. Means are provided for independently releasably locking the horizontal support members in selected positions with respect to each other; in the case of cantilever arms, the support members preferably extend outwardly from opposite sides of the rail at acute angles with respect thereto. A pair of vertical guide members are individually slidably mounted upon the horizontal support members for longitudinal movement therealong; means are provided for releasably locking the vertical guide members in selected positions on their respective support members and on opposite sides of the rail. A pair of impacting devices are supported upon the frame for vertical movement with respect to the vertical guides and to the rail; these impacting devices are employed simultaneously to drive a pair of fastening devices into a railway tie underlying the rail. In addition, the apparatus includes means individually interconnecting the impacting devices and the vertical guides to retain the impacting devices in predetermined spaced relation with respect to the vertical guides. during vertical movement of the impacting devices, thereby maintaining accurate vertical alignment of the impacting devices during operation of the apparatus.

Other and further objects of the present invention will be apparent from the following description'and claims and are illustrated in the accompanying drawingswhich, by way of illustration, show a preferred embodiment of the present invention and the principles thereof and what I now consider to be the best mode in which I have contemplated applying these principles. Other embodiments of theinvention embodying the same or equivalent principles may be used and. structuralchangesmay be made from the present invention and the purview of pended claims.

In the drawings:

Fig. 1 is a plan view of an impacting apparatus constructed in accordance with the inventive concept and illustrating the novel suspension and alignment system of the invention;

'Fig. 2 is an elevation view of the impacting apparatus illustrated in Fig. 1; and

Fig. 3 is a detail sectional view or" a portion of the apparatus taken along line 3-3 in Fig. 2.

In the plan View of Fig. 1, there is illustrated a railway including the usual pair of rails and 11 interconnected by a series of ties 12. Rail 10 has already been fastened to the ties by means of tie plates 13, retaining devices illustrated as spikes 14, and anchoring devices as indicated by the studs 15. The impacting apparatus of the invention, generally indicated at 20, is shown in position for driving retaining devices such as the "spikes 14 into the ties 12 to secure the second rail 11 thereto.

Impacting apparatus 20 comprises a frame 21 including four horizontal frame members 22, 23, 24, and 25 which are welded or otherwise suitably secured to each other in rectangular configuration. The configuration and dimensions of frame 21 are not particularly critical, although it is preferable that the frame be generally symmetrical with respect to rail 11 in order to simplify balancing of the impacting apparatus with respect to the rail. Frame 21 further includes a pair of extension members 26 and 27 aflixed to frame member 24 and extending outwardly therefrom in a direction parallel to rail 11; a first rail-engaging wheel comprising two flanged wheel segments 28 and 29 is supported between frame extension members 26 and 27, the relative spacing between the frame extension members and wheel segments being determined by a series of spacer or washer members 30. Thus, by varying the thickness of spacer members 30, the rail-engaging wheel comprising the two segments 28 and 29 may be effectively adjusted in width to engage rails of different types and sizes. Similarly, a pair of frame extension members 32 and 33 are affixed to and extend from frame member 22 in a direction parallel to rail 11 and opposite to extension members 26 and 27; frame extension members 32 and 33 are utilized to support a rail-engaging wheel assembly comprising two flanged wheel segments 34 and 3S and a plurality the ap- 'of spacers 36. An additional frame extension or outrigger member 37 is afiixed to frame 21 and extends therefrom in a direction transverse to the railway; outrigger 37 is employed to support an additional wheel 38 which enegages rail 10 and serves to balance the impacting apparatus upon the railway. Preferably, outrigger -37 is made adjustable in length and is arranged for extension either from the side of frame '21 afforded by frame member 25 or that formed by frame member 23,

for reasons to be explained more fully hereinafter. 'Suitable mounting arrangements for the outrigger are described in detail in the aforementioned copending Godfrey and Johnson applications.

A bracket 40 is pivotally mounted upon a frame member 42 extending between frame extension members 26 and 27 and is utilized to support a rubber tired wheel 41 adjacent member 27, the position of wheel 41 with respect to frame 21 and rail 11 being most clearly indicated in Fig. 2. Bracket 40 is maintained in position by means of a pin 43 and may be pivoted to re-locate wheel 41 adjacent extension member 26. Similarly, a

secondbracket 44 is pivotally mounted'on a member 45 extending between frame extension'members 32 and 33 adjacent member 33 and is employed to support a second rubber tired wheel 46, bracket 44 being held in position by'means of a locking pin 47.

Frame 21 further includesa 'main vertical .support member 50 which is welded or otherwise suitably afiixed to frame 24 and is centered between frame extensions 26 and 27 so as to be located directly over the center of rail 11. A pair of angle braces 51 and 52 may be provided interconnecting support post 50 with the frame extension members to afford added rigidity to the vertical support member. A second or auxiliary vertical support member '53 is affixed to frame member 22 and is braced by a pair of brace members 54 and 55. As best indicated in Figs. 1 and 2, a collar 56 is fixedly supported upon post 50; the collar may be mounted upon the support post by any suitable means which effectively prevents axial movement of the collar with respect to the support member. A pair of mounting links 57 and 58 are disposed in encompassing relation to vertical support member 50 and are supported in predetermined vertical position upon support member 50 as best shown in Fig. 2. A spacer 59 may be utilized to vary the relative height of the support links 57 and 58 with respect to the base of the impacting apparatus if desired.

A supporting cross bar 60 is suspended from vertical supporting member 50 by a linkage comprising a clevis 61, a link 62, and a handle structure 63 including handle extensions 63A and 63B. Clevis 61 is afiixed to cross bar 60 by bolts or other suitable means and is pivotally connected to one end of the link 62, the other end of link 62 being pivotally connected to the end of handle structure 63. Handle structure 63, in turn, is supported for pivotal movement in a vertical direction with respect to the end of vertical support member 50, the desired pivotal mounting being afforded by a pin 64. The operating linkage comprising handle 63, link 62, clevis 61, and cross bar 60 is shown in the inactive or non-operating position for the impacting apparatus and may be locked in that position by means of a chain or similar device 65 connecting the handle 63 to frame 21.

A pair of impacting devices 70 and 71 are supported from cross bar 6t). The impacting devices may comprise conventional air hammers and may be connected to an external source of compressed air (not shown) for actuation as by a pair of coupling hoses 72 and 73 having a common inlet connection 76 as illustrated in Fig. 2, the inlet coupling 76 being supported upon the auxiliary support post 53. The connection between the air hammers and cross bar 60 is not a fixed one in the sense that the hammers are located at fixed longitudinal positions on the cross bar; rather, the hammers are so supported that they may be slidably adjusted longitudinally of the cross bar in order to vary the separation between the two hammers. This relationship between the cross bar and the two air hammers is best illustrated in Figs. 1 and 3, which indicate the range of adjustment of the individual hammers along the two slots 74 and 75 which limit the relative movement of hammers 70 and 71 respectively along the length of the cross bar. It is of course desirable to afford a certain degree of resiliency in the air hammer-cross bar connection, in order to avoid undue vibration and jarring of the impacting apparatus during operation of the hammers, the resilient connection being afforded by mounting springs 76 and 77.

The impacting apparatus 29 further includes a pair of horizontal cantilever support members 79 and 80 which are affixed to collars 57 and 58 respectively. Cantilever support members 79 and 80 may be tubular in form, as indicated in the drawing, or may be formed from bar stock, although the tubular configuration is preferable from a weight standpoint. Moreover, it is preferred that the support members be triangular, rectangular as shown, or otherwise polygonal in cross sectional configuration, rather than round, in order to inhibit pivotal movement of the impacting devices 70 and 71 with respect to the support members, as will be made apparent hereafter.

A first sleeve 81 having a cross-sectional configuration corresponding to cantilever support member 79 is fitted over cantilever support member 79 to be slidably adjustably mounted on the horizontal support member. 'Means are provided for locking the sleeve 81 in any desired position along the length of the cantilever support memher as indicated by a setscrew or other similar locking device 82. Two vertical guide members comprising rods 83 and 84 are afiixed to the sleeve 81 in predetermined spaced relation with respect to each other. A pair of guide sleeves 85 and 86 are freely slidably mounted upon thevertical guide rods 83 and 84 respectively; these two vertical guide sleeves are connected to hammer 70 by mounted upon cantilever member 80 and may be afiixed thereto by locking means comprising a set screw 93 or similar device. Two vertical guide rods 94 and 95 are afixed to sleeve 92 and a pair of vertical guide sleeves 96 and 97 are individually slidably supported upon rods 9'4 and 95 respectively. As indicated in Fig. 3, the two vertical guide sleeves 96 and 97 are interconnected by a yoke 98, the center portion of which is atlixed to hamme: 71 as by a mounting plate 99 and a plurality of mounting bolts 100. Consequently, vertical movement of hammer 71 is aligned and guided by the connection rods 94 and 95.

In order to place impacting apparatus in operation, the apparatus is first located on the rail 11 in the position shown in Fig. l with the two hammers 70 and 71 approximately over thetie plate opening through which the two spikes, studs, or other fastening devices are to be driven. The relative positions of the two hammers are then adjustedto accurately align them with the openings in the tie plate. The alignment procedure may be varied substantially, I ing devices which hold cantilever members 79 and 80 in their given angular relationship, these locking devices comprising the set screws or similar devices 101 and .102 shown in Fig. 2. At the same time, the locking devices .82 and 93 are released to permit longitudinal sliding move- I ment of sleeves 81 and 92 along the cantilever members. In addition, it is usually necessary to release the interlocking connections between the two hammers and cross bar 60 to permit movement of the two hammers longitudinally relative to the cross bar.

The cantilever support member 79 is adjusted in angular position so that it extends directly over the opening in the tie plate on one side of rail 11 through which the fastening device is to be driven. Set screw 101 is then tightened to lock collar 57 and cantilever support arm 79 rigidly on post 50 in this desired position. Similarly, cantilever support arm 80 is displaced angularly until it is lo- :cated directly above the opening in the tie plate on the opposite side of rail 11 through which the second fastening ,device is to tightening set screw 102 in collar 58. After cantilever ,support 79 is in position, sleeve 81 is moved longitudinally of the cantilever arm until hammer 70 is accurately aligned .with the desired hole in the tie plate andis then locked in that position by means of locking device 82. Similarly, I,

after cantilever arm 80 has been aligned in the desired angular position, sleeve 92 is adjusted along the cantilever --ar m and locked in position by device 93. Thereafter, the ltwo hammers are again locked to the cross bar 60. It is --only necessary that this adjustment be carried out once for a given size rail and a given pair of fastening device positions on the tie plates, since the tie plates for a given railare uniform in size and the apertures are uniformly ,located with respect to the rail. After adjustment of the horizontal guides hammers with the desired apertures in the tie plates, the

to align the p but may be accomplished by loosening the lockbe driven and is fixed in that position by machine is ready for operation. A suitable source of compressed air is connected to hammers'70 and 71 by the couplings comprising hoses 72 and 73 and coupling 76. Chain is disconnected from handle 63 and the impacting apparatus is guided along rail 11 until the two hammers are located directly above a pair of spikes to be driven. In this connection, it should be noted that the impacting devices may be provided with special guiding heads to aid in alignment of the hammers with the spikes, the hammer construction described and claimed in the aforementioned application of Godfrey and Johnson, Ser. No. 509,297 being preferred.

With the impacting apparatus in position, handle 63 is raised, the handle pivoting about pin 64 in post 50 and acting to lower the cross bar 60 by means of the linkage comprising clevis 61 and link 62. The downward movement of the cross bar impels hammers and 71 down wardly, the vertical movement of the two hammers being accurately guided by virtue of their connection to the guide rods 83, 84, 94, and 95 through the yokes 87 and 98 and the sleeves 85, 86, 96, and 97. Downward movement of the hammers may also be utilized to actuate control valves for the pneumatic hammers and thereby start them in operation, as described in the aforementioned copending Godfrey and Johnson applications. The hammers are moved downwardly by the operator of the appar'atus until the two spikes or other fastening devices are driven completely, the fully'depressed position of impacting d'evice'7 0 being shown at 70A in Fig. 2. Handle 63 is then depressed to raise the hammers clear of the fastening devices and interrupt operation of the hammers. The operator then pushes forwardly on the handle, as indicated by arrows A in the drawings, until the impacting apparatus is located over the next pair of fastening devices to be driven, at which time the handle is again depressed to lower and actuate the two hammers. Accordingly, the apparatus acts to drive two spikes simultaneously on opposite sides of the rail 11 in each tie plate without requiring adjustment of the hammer positions by the operator for individual tie plates and with a minimum requirement foroperational skill. I

' When it is desired to remove apparatus 20 from the railway, it is only necessary to lift outrigger shaft 37, tilting the apparatus until wheels 41 and 43 engage the ground adjacent the railway. The apparatus is then easily rolled free of the railway. Placing the apparatus on the railway is equally simple; it is rolled up to a point closely adjacent the rail and then tilted until the flanged wheels 28, 29 and 34,35 engage the rail as indicated in Figs. 1 and 2. As noted above, the outrigger and its wheel 38 serve to stabilize and balance the apparatus during operation. Moreover, the machine is readily adapted for operation in the opposite direction and/ or on the opposite side of the railway. This is accomplished by removing pins 43 and 47, pivoting brackets 40 and 44 to their alternate positions adjacent members 26 and 32 respectively, and replacing the pins in their alternate receptacles to lock the brackets in place. It is also necessary to reverse the direction of extension of outrigger 37, by removing the outrigger from frame 21 and re-mounting it thereon so that it extends outwardly from frame member 23 rather than frame member 25.

The cantilever suspension and guiding arrangement of the invention has several marked advantages in operation. By locating the entire guide arrangement well above the railway surface, the area adjacent the operating heads of hammers 70 and 71 is cleared completely, thereby avoiding any obstruction to the vision of the operator and permitting maximum accuracy in alignment of the inipacting devices with the spikes or other fastening device to be driven. Moreover, the novel angular guide arrangement comprising cantilever arms 79 and alfords a highly simplified and convenient means for aligning the hammers accurately with respect to the holes in the tie plate throughwhich' the spikes are to be driven.

Hence, while I have illustrated and described the preferred embodiment of my invention, it is to be understood that this is capable of variation and modification, and I therefore do not wish to be limited to the precise details set forth, but desire to avail myself of such changes and alterations as fall within the purview of the following claims.

I claim:

1. Apparatus for driving spikes or like fastening devices into a railway tie comprising: a frame; rail-engaging wheels mounted upon said frame, for transporting and guiding the apparatus along a railway rail; a pair of elongated horizontal support members mounted on said frame above said rail for independent pivotal movement with respect to a common vertical axis; means for independently releasably locking said horizontal support members in selected angular positions with respect to each other with said support members extending outwardly from opposite sides of said rail at acute angles with respect thereto; a pair of vertical guide members, individually slidalbly mounted upon respective ones of said horizontal support members for longitudinal movement therealong; means for releasably locking said vertical guide members in selected longitudinal positions on said elongated support members and on oppositesides of said rail; impacting means, comprising a pair of impacting devices, for simultaneously driving a pair of said fastening devices into a railway tie underlying said rail said impacting means further including means connected to said frame and to said impacting devices for supporting said impacting devices upon said frame for vertical movement with respect to said vertical guides and said rail; and means, individually interconnecting said impacting devices with respective ones of said vertical guides, for retaining said impactingdevices in predetermined spaced relation with respect to said vertical guides to maintain said impacting devices in accurate vertical alignment during driving of said fastening devices.

2. Apparatus for driving spikes or like fastening devices into a railway tie comprising: a frame, including a vertically extending main support member; rail-engaging wheels, mounted upon said frame, for transporting and guiding the apparatus along a railway rail with said main support member approximately centered above said rail; a pairof elongated horizontal support members mounted on said main support member adjacent the upper end thereof for independent pivotal movement with respect to a common vertical axis extending through said rail; means for independently releasably locking said horizontal support members in selected angular positions with respect to each other with said horizontal support members extending outwardly from opposite sides of said rail at acute angles with respect thereto; a pair of downwardly extending vertical guide members, slidably mounted upon respective ones of said horizontal support members for longitudinal movement therealong; means for releasably locking said vertical guide members inselected longitudinal positions on said elongated horizontal support members and on opposite sides of said rail; impacting means, comprising a pair of impacting devices, for simultaneous ly driving a pair of said fastening devices into a railway 'tie underlying said rail said impacting means further including means connected to said main support member and to said impacting devices for supporting said impacting device upon said main support member for vertical movement with respect to said vertical guides and said rail; and means, individually interconnecting said impacting devices and with respective ones of said vertical guides, for retaining said impacting devices in predetermined spaced relation with respect to said vertical guides 'to maintain said impacting devices in accurate vertical alignment during driving of said fasteningdevices.

3. Apparatus for driving spikes or like fastening devices into arailway tie comprising: a frame, including a vertically extending mainsupport member; rail-engaging 8 I wheels, mounted upon said frame, for transporting and guiding the apparatus along a railway rail; 21 pair of elongated horizontal cantilever support members mounted on said main support member for independent pivotal movement with respect to a common vertical axis extending through said rail; means for independently releasably locking said horizontal support members in selected angular positions with respect to each other with said support members extending outwardly from opposite sides of said rail at acute angles with respect thereto; a pair of positioning sleeves, individually slidably mounted upon respective ones of said horizontal support members for longitudinal movement therealong; means for releasably locking said sleeve in selected longitudinal positions on said elongated horizontal support members and on opposite sides of said rail; two pair of vertical guide rods the rods of each pair respectively being atfixed to one of said sleeves and depending therefrom in predetermined spaced relation with respect to each other; impacting means, comprising a pair of impacting devices, for simultaneously driving a pair of said fastening devices into a railway tie underlying said rail, said impacting means fur-' ther including means connected to said frame and to said impacting devices for supporting said impacting devices upon said frame for vertical movement with respect to said vertical guides and said rail; and means comprising a pair of yokes individually interconnecting each of said impacting devices to one respective pair said vertical guides to retain said impacting devices in predetermined spaced relation with respect to said vertical guides and maintain said impacting devices in accurate vertical alignment during driving of said fastening devices.

4. Apparatus for driving spikes or like fastening devices into a railway tie comprising: a frame, including a vertically extending main support member; rail-engaging wheels, mounted upon said frame, for transporting and guiding the apparatus along a railway rail; a pair of elongated horizontal cantilever support members mounted on said frame above said rail for independent pivotal movement with respect to a common vertical axis; means for independently releasably locking said horizontal support members in selected angular positions with respect to each other with said support members extending outwardly from opposite sides of said rail at acute angles with respect thereto; a first pair of vertical guide members, slidably mounted upon one of said horizontal support members in spaced relation with respect to each other for longitudinal movement therealong, said vertical guide members extending downwardly from said support member; a second pair of vertical guide members, slidably mounted upon the other of said horizontal support members and extending downwardly therefrom; means for releasably locking said pairs of vertical guide members in selected longitudinal positions on said elongated horizontal support members and on opposite sides of said rail; impacting means, comprising a pair of impacting devices, for simultaneously driving a pair of said fastening devices into a railway tie underlying said rail, said impacting means further including means connected to said main support member and to said impacting devices for supporting said impacting devices upon said main support member for vertical movement with respect to said vertical guides and said rail; means, individually interconnecting said impacting devices with respective .ones of said pairs of vertical guides, for retaining said impacting devices in predetermined spaced relation-with respect to said pairs of vertical guides to maintain said impacting devices in accurate vertical alignment during driving of said fastening devices; and actuating means mechanically connected -to said impacting devices, for concurrently impelling said devices downwardly and for actuating said devices.

5. Apparatus for driving spikes or like fastening devices into a railway tie comprising: a frame, including a vertically extending main support member; rail-engaging wheels, mounted upon said frame, for transporting and guiding the apparatus along a railway rail; a pair of linear horizontal support members mounted on said main support member adjacent the top thereof for independent horizontal pivotal movement with respect to said rail; means for independently releasably locking said horizontal support members in selected angular positions with respect to each other and extending outwardly from opposite sides of said rail; a pair of vertical guide members, individually slidably mounted upon respective ones of said horizontal support members for longitudinal movement therealong with said vertical guide members extending downwardly from said horizontal support members; means for releasably locking said vertical guide members in selected longitudinal positions on said horizontal support members and on opposite sides of said rail; impacting means, comprising a pair of impacting devices, for simultaneously driving a pair of said fastening devices into a railway tie underlying said rail, said impacting means further including means connected to said main support member and to said impacting devices for supporting said impacting devices upon said main support member for vertical movement with respect to said vertical guides 10 and said rail; and means, individually interconnecting said impacting devices with respective ones of said vertical guides, for retaining said impacting devices in predetermined spaced relation with respect to said vertical guides to maintain said impacting devices in accurate vertical alignment during driving of said fastening devices,

References Cited in the file of this patent UNITED STATES PATENTS 1,321,909 Hastings Nov. 18, 1919 1,351,246 Hastings Aug. 31, 1920 2,303,245 Weyandt Nov. 24, 1942 2,591,005 Piper Apr. 1, 1952 2,602,666 Burke et al July 8, 1952 FOREIGN PATENTS 1,071,657 France Mar. 10, 1954 OTHER REFERENCES Bulletin 199 (1953), Nordberg Mfg. Co., Milwaukee 1,

WIS.

Bulletin 220 (1953), Nordberg Mfg. Co., Milwaukee 1, Wis. 

